Ultrasonic cutting is a term used for a very varied range of procedures. What they have in common is that a cutting process is assisted, or even actually made possible, by mechanical vibration.
1. Cutting textiles
Thermoplastic materials (woven, non-woven or knitted) get drawn through a sonotrode-anvil combination. The vibration and the resultant change of pressure within the material causes it to become plasticised and it gets separated by the anvil shape. The edge gets simultaneously sealed.The speeds that can be achieved depend on many factors. Speeds achieved in practice are 0.5 to 200m/min.
2. Cutting foodstuffs
In contrast to the ‘crimp cutting’ mentioned above, here the cutting is done using a sonotrode fitted with a blade. The blade is generally bevelled on its leading edge and the cut is performed in guillotine style. In addition to applications in the foodstuffs sector, these tools are also used in other areas, for example for cutting (raw) rubber, elastomers and plastics.
3. Cutting rigid fibres
In the mid-1990s, carbon fibre began its success story. Great rigidity combined with low weight was ideal for use in aircraft construction. One problem was the cutting technologies available.
However, ultrasonic cutting using tungsten carbide blades produced outstanding results. One of the leading players in the development of this combination was Jürgen Keppel, now the company’s managing director.
Based on our knowledge and market requirements, standard systems were already being developed by 2004, which clients were able to use straight ‘off the shelf’.
Today these established ultrasonic cutting systems are regularly used for composites in rotor blade manufacture, vehicle production and the aviation industry. They are increasingly being used to cut combinations of materials such as carbon fibre, glass fibre, aramid fibre and basalt fibre.